It is important for magnetic storage devices using a magnetic tunneling junction (magnetoresistance effect element) to control the shape of the magnetic tunneling junction. If etching is performed too excess in patterning a magnetic tunneling junction film, it is likely that a redeposition layer formed on the side surface of a magnetic tunneling junction at the time of the etching will cause a short-circuit between magnetic layers between which a tunnel barrier layer is interposed. If etching is not fully performed to the contrary, there is a possibility that adjacent magnetic tunneling junctions will not completely be separated from each other.
It is thus desirable that a magnetic storage device using a magnetic tunneling junction should be configured by a method to allow the magnetic tunneling junction to function with reliability.